Development of pre-dried and blended lime mortars for the ready-mix market

Extract

[...] construction industry are experiencing the effects of the economic downslide, and one can expect this downturn to last for six to 18 months, according to Associated Construction Publications in their 2008 National Ready-Mix Concrete Association Industry Snapshot report. Sources Allen, L. W., and T. Z. Harmathy. Determination of Equivalent Thickness of Concrete Masonry Units. National Research Council of Canada, Division of Building Research, Building Research Note Allen, L. W. Fire Endurance of Selected Non-load bearing Concrete Masonry Units. National Research Council of Canada, Division of Building Research, NRC Ashurst, John, Mortars, Plasters and Renders in Conservation. [...]

[...] This is highly related to how lime is prepared and used in both the ready-mix and construction industry, as well as in the conservation realm The drying of sand for use in mortars Sand is a common ingredient in the paste called mortar, commonly made from a mixture of water, cement and an additional aggregate such as sand, as well as other forms of binders such as cement or lime.[4] Sand is usually a prime component of concrete, and is first dried before use. [...]

[...] Technically speaking, burning and slaking procedures are more complex for the blended and pre-dried mortar limes, over chalk or other pure limes, but this is a price to pay for the extreme versatile of the product. The property of the hydraulic lime is dependent upon the burning and slaking needs, and therefore new technological developments have created a much easier process for knowing the exact chemical analysis and production data to garnet burning and slaking times and temperatures. Non-hydraulic lime comes in the form of putty and is mostly hydrated. [...]

[...] The following shows a general outline of NHL types: NATURAL HYDRAULIC LIME 5 This type of lime has a high grade of strength, plasticity, elasticity, and is used in mortars, for both bedding and pointing. NATURAL HYDRAULIC LIME 3.5 This is the most commonly used lime, with a very white color, making for high aggregation of sand. NATURAL HYDRAULIC LIME 2 This lime is used for interiors and weak structures, as well as building and structure conservation work on deteriorated masonry, weak masonry or where the structure was built using soft materials. [...]

[...] Chapter Literature Review Asher (2002) states that there is a revival of interest in non-hydraulic lime putty, recognizing the important role that hydraulic limes play in the context of mortar and plaster for the Ready-Mix market. Not only are these limes the most appropriate material, but studies show that lime and cements are highly recommended to the non-manageable types of cement. Stud (1985) maintains that the extensive use of PC mortar can “only indicate ignorance on the qualities of natural hydraulic limes.” According to Farrington (2004), there are many advantages to using pre-dried lime mortar mix for the Ready-mix market, including the following reasons: It creates a chemical set before full shrinkage occurs, which reduces the risk of cracking. [...]